This is really easy:
Vestir roupa = wear or put on clothes or dress, [visto x: I wear x.]
Calçar sapatos = wear or put on shoes. [for footwear]
These are used when discussing sizes worn: Visto um (tamanho) 36. Calço um (tamanho) 42.
What size do you wear? [shoes] Que tamanho você calça?
What size do you wear [clothes] Que tamanho você veste?
Visto is the simple present: I wear or put on some item of clothing.
Please note: both those can be wear in English, but you should not confuse the ones for shoes and the one for clothes. If you can remember that sidewalk is Calçada, where you walk, that should help you remember: calçar sapatos.
Usar= to wear; shoes, clothes, jewelry, watches, hats, etc.
- Uso calça comprida no trabalho.
- I wear long pants at work.
- Já não uso relogio. [I no longer wear a watch.]
Usar is used for something worn regularly. To be worn.
- Do you wear a hat everyday? Você usa chapéu todos os dias?
You will have to learn the verbs by heart: vestir, calçar, usar, botar.
The good news: four verbs with an AR ending, and one with an IR ending. You can look up those conjugations and tenses, I am not putting them all up here.
The verb vestir is only irregular in the first person singular, present tense: Eu visto. (That makes the subjunctive be: vista, as subjunctives comes from that tense and person. But that's quite advanced.)
Special note about botar: botar should be used like this: He put on his flips flops when he went to the beach. (Ele botou as havianas quando foi à praia.)
Botar can be used in the sense of PUT ON.
- Put on your shoes right now. Bota os sapatos agora mesmo.
Vestir and botar both mean to put on. But vestir is more formal and botar is more informal and used in the sense of: PUT ON for a purpose.
- He dresses very well. Ele se veste muito bem.
- He puts on a coat when its cold. Ele bota um casaco quando faz frio.
Finally, instead of botar, you can use por for put on, but the verb por is highly irregular.
Eu nunca ponho havaianas em casa. I never put on flip flops at home.
[This is perhaps not the full story, but it is at least half of it].